1. Field of the Invention
The invention relates to the field of fluid transfer apparatus for refueling an aircraft, and particularly to an apparatus for refueling vertical and/or short take off and landing aircraft from a ship.
2. Description of Prior Art:
Because vertical and/or short take off and landing aircraft (V/STOL) can hover or travel at extremely small horizontal speeds, it is possible to refuel such aircraft from ships at sea. The problem has been how to connect the ship to the aircraft and yet accommodate the relatively large displacements or position changes of the ship due to heave, roll, and pitch, or combinations thereof. Conventional ship-to-ship or ship-to-shore type fuel transferring apparatus, such as disclosed in U.S. Pat. Nos. 3,805,834, Double Counterbalance Marine Loading Arm by P. J. Bily; 3,889,728, Marine Loading Arm For Bunkering Vessels by R. M. Riche; 4,109,688, Attitude Maintaining Mechanism For A Marine Loading Arm by N. E. Jameson; and 4,142,551, Hydraulically Balanced Marine Loading Arm by C. A. Wilms are not particularly suitable for coupling to an aircraft. Even though these refueling booms are typically counterbalanced and incorporate swivel joints in both the vertical and horizontal planes, inertia and friction loads would still be coupled to the aircraft as the ship changed position. This would make control of the aircraft difficult, especially when in the hovering mode.
Aircraft to aircraft type refueling systems, such as disclosed in U.S. Pat. No. 4,072,283, Aerial Refueling Boom Articulation by R. H. Weiland, are also unsuitable. Refueling of conventional aircraft in flight is accomplished by use of tanker aircraft such as the United States Air Force KC-135. The aircraft to be refueled is brought into close proximity to the rear of the tanker and velocities are matched. A refueling boom is then extended and lowered, typically controlled by an operator in the tail of the tanker. The pilot of the aircraft to be refueled and the boom operator maneuver the aircraft and boom, respectively, to accomplish coupling. The boom, typically, incorporates ruddervators mounted at the end of the boom which provide both vertical and horizontal position control. Unfortunately, the use of aerodynamic control surfaces for positioning a refueling boom on board a ship would not be effective because of the ship's slow speed, unless they were made extremely large.
Also of interest in U.S. Pat. No. 1,869,487, Fuel Supplying Apparatus For Aircraft, by L. Lefevre, et al. Lefvevre, et al. disclose a horizontal refueling boom rotatably mounted to a tower. The boom is rotated and the aircraft flies in a circle at the same rotational velocity. Thereafter, the crew couples a hose to a fuel inlet on the aircraft. Here the problem is that there is no means to compensate for the ship's position and a rotating boom is not required for a V/STOL aircraft because of their ability to hover.
Therefore, it is a primary object of this invention to provide an apparatus for refueling a V/STOL aircraft from a ship at sea.
A further object of this invention is to provide a refueling apparatus for refueling a V/STOL aircraft from a ship at sea that minimizes loads induced into the aircraft by movement of the ship.
A still further object of this invention is to provide a refueling apparatus which maintains the point of connection to the V/STOL aircraft in a substantially constant position eliminating the effects of ship changes due to heave, roll, and pitch, or combinations thereof.